Better readme comments

Author: benjaminleighton

README.md

@@ -129,12 +129,15 @@ You can alter default [Flask](http://flask.pocoo.org/docs/1.0/config/) or
     # Default product to display (picks first available)
     CUBEDASH_DEFAULT_PRODUCTS = ('ls8_nbar_albers', 'ls7_nbar_albers')
 
-    # Limited regex syntax and group name pairs can be used to group matches on product name. 
+    # Limited regex syntax to match product names with a user-defined group.
+    # Pairs of regex,group are ";" separated. Regex and group are "," separated.
+    # As such ";" and "," can't be used in the regexs.
+    # eg ".albers., Albers projection; level1, Level 1 products"
+    # If re.search(regex, product name) then return the corresponding group.
+    # If CUBEDASH_PRODUCT_GROUP_BY_REGEX string parses then regex matching will be used in place of CUBEDASH_PRODUCT_GROUP_BY_FIELD.
+    # If CUBEDASH_PRODUCT_GROUP_BY_REGEX string is malformed an error will be logged and we default back to CUBEDASH_PRODUCT_GROUP_BY_FIELD.
     # eg ".*albers.*,Albers projection;level1,Level 1 products" 
-    # regex and group name seperated with, and pairs thereof with ; 
-    # multiple regexs can match to target then same group but if multiple regexes match a product only the first group is assigned 
-    # if defined overrules CUBEDASH_PRODUCT_GROUP_BY_FIELD 
-    CUBEDASH_PRODUCT_GROUP_BY_REGEX = ".*albers.*,Albers projection;.*level1.*,Level 1 products"
+    CUBEDASH_PRODUCT_GROUP_BY_REGEX = None 
     # Which field should we use when grouping products in the top menu?
     CUBEDASH_PRODUCT_GROUP_BY_FIELD = 'product_type'
     # Ungrouped products will be grouped together in this size.